Plants and factories utilize process control devices to control the flow of fluids in processes, wherein “fluids” may include liquids, gases, or any mixture that can flow through a pipe. Manufacturing processes that create consumer articles or goods such as fuel, food, and clothes require control valves to control and regulate fluid flow. Even a medium sized factory may utilize hundreds of control valves to control a process.
When designing a process, the designer is faced with many design requirements and design constraints. For example, some process control applications require a valve to enable flow in two directions, which are often called bi-directional flow valves. Another example of a design constraint includes the pressure at which the fluid will be operating within the process. For example, some processes operate at relatively low pressures, e.g., less than approximately 10,000 pounds per square inch gauge (psig), while other processes may operate at relatively high pressures, e.g., greater than 10,000 psig, and up to approximately 20,000 psig.
In certain circumstances, a 2-way or bi-directional valve may not be sufficient to achieve the desired functionality for a selected part of the system. Accordingly, designers wishing to equip a process system with a 3-way functionality may opt to use a tri-directional or 3-way valve. However, in comparison to 2-way valves, 3-ways valves can have various drawbacks. For example, due to the multiple flow paths, typical 3-way valves use tortured flow paths through the valve and have inefficient flow between the inlet and outlet ports of the valve. The current designs also require large forces to actuate the valve, many times to overcome the pressure of the operating fluid flowing through the valve, and to fully close the valve, which increases the actuation time, requires larger valves to accommodate the larger volume required for activation, and may require large actuators as part of the valve. Finally, current 3-way valves come in standard sizes with standard connectors at each port, which requires manufacturers and retailers to manufacture and stock a large number of different variations of 3-way valve.